Unmasking Rheumatic Heart Disease in Pregnancy.

Pregnancy imposes significant hemodynamic stress that can unmask underlying cardiac disease. In women with rheumatic mitral stenosis, increased plasma volume and cardiac output may precipitate pulmonary congestion and heart failure, posing substantial maternal and fetal risk. A 38-year-old woman at 24 weeks of gestation presented with one week of progressive dyspnea and orthopnea, prompting suspicion for a cardiac etiology. Examination revealed tachycardia, hypertension, and a diastolic murmur at the apex. Transthoracic echocardiography demonstrated severe rheumatic mitral stenosis (mitral valve area = 0.9 cm², mean gradient = 9-10 mmHg), confirmed on transesophageal echocardiography with no left atrial thrombus. Despite medical stabilization with beta blockers and diuretics, symptoms persisted. Percutaneous balloon mitral valvuloplasty was favored over surgical intervention due to suitable valve anatomy and to avoid cardiopulmonary bypass, which carries a higher fetal loss risk in pregnancy. The procedure was performed with multidisciplinary coordination involving cardiology and maternal-fetal medicine, with continuous fetal monitoring. Following successful dilation with a 28-mm Inoue balloon, the mitral valve area increased to 1.9 cm², with rapid resolution of pulmonary edema. Both maternal and fetal outcomes were favorable at discharge.